Excludes1 pair
I01.2 vs I40-
I01.2 and I40 are not coded together. ICD-10-CM declares them mutually exclusive with an Excludes1 note — the two conditions are not expected to occur together, so exactly one of them is normally correct for a given encounter. The Official Guidelines carve out one exception: if the two conditions are clearly unrelated to each other, both may be reported.
The official note, declared on I40
acute rheumatic myocarditis (I01.2)
I01.2
Acute rheumatic myocarditis
Billable
- Chapter 9
- Diseases of the circulatory system
- Section
- I00-I02
Use when the record says
- Any condition in I00 with myocarditis
Indexed under
- Myocarditis › active › rheumatic
- Myocarditis › acute or subacute › rheumatic
- Myocarditis › rheumatic › active or acute
- Rheumatic › myocarditis › active or acute
- Degeneration, degenerative › myocardial, myocardium › with rheumatic fever › active, acute or subacute
I40
Acute myocarditis
Not billable
- Chapter 9
- Diseases of the circulatory system
- Section
- I30-I5A
Use when the record says
- subacute myocarditis
Excludes1 is not always absolute: where two conditions covered by the note are genuinely unrelated, CMS guidance permits reporting both. Document the reasoning rather than assuming it. More on Excludes1 vs Excludes2 · FY2027